fallar
(Verb)
"to fail"
From Latin fallare "to deceive," "to mistake."
From Proto-Italic *faln-e/o- 'id.' From Proto-Indo-European *sgwhel-n- "to stumble."
According to Tibón (1988), fallar is the origin of the surname de Falla. He also writes that the word is not the origin of the surname de Falla found in Valencia, though he states this without further explanation.
Indo-European

Romance

Portuguese falhar, French faillir, Italian fallare

Hellenic

Ancient Greek σφάλλομαι (sphállomai) "to fall," "to be ruined"

Armenian

Armenian sxalem "to fail"

Indo-Iranian

Sanskrit skhalate "to stumble," Middle Persian škarwīdan 'id.'

de Vaan, M.
Etymological Dictionary of Latin and Other Italic Languages.
BRILL.
2014.